METHODS FOR OBTAINING. HOLLOW NANO-STRUCTURES

Methods are provided for obtaining hollow nano-structures which include the steps of providing a Suspended film starting layer on a Support Substrate, depositing on the starting layer a sacrificial layer, performing, in progressive sequence, a com plete erosion phase of said Support Substrate and starting layer and performing an at least partial erosion phase of the sacri ficial layer previously deposited on the starting layer so as to obtain holes passing through the starting layer and passing or non passing through the sacrificial layer, depositing, on the side of the support substrate opposite to that where the start ing layer is put, at least one covering layer arranged to inter nally cover the holes created by the progressive erosion. Hol low nano-structures formed by Such methods are also provided

Mapping the local dielectric response at the nanoscale by means of plasmonic force spectroscopy

At the present, the local optical properties of nanostructured materials are difficult to be measured by available instrumentation. We investigated the capability of plasmonic force spectroscopy of measuring the optical response at the nanoscale. The proposed technique is based on force measurements performed by combining Atomic Force Microscopy, or optical tweezers, and adiabatic compression of surface plasmon polaritons. We show that the optical forces, caused by the plasmonic field, depend on the local response of the substrates and, in principle, allow probing both the real and the imaginary part of the local permittivity with a spatial resolution of few nanometers

A microfluidic device that separates cells

è un dispositivo e metodo che attraverso un sistema microfuidico munito di membrana separa le cellule in funzione delle loro dimension

Information in a network of neuronal cells: Effect of cell density and short-term depression

Neurons are specialized, electrically excitable cells which use electrical to chemical signals to transmit and elaborate information. Understanding how the cooperation of a great many of neurons in a grid may modify and perhaps improve the information quality, in contrast to few neurons in isolation, is critical for the rational design of cell-materials interfaces for applications in regenerative medicine, tissue engineering, and personalized lab-on-a-chips. In the present paper, we couple an integrate-and-fire model with information theory variables to analyse the extent of information in a network of nerve cells. We provide an estimate of the information in the network in bits as a function of cell density and short-term depression time. In the model, neurons are connected through a Delaunay triangulation of not-intersecting edges; in doing so, the number of connecting synapses per neuron is approximately constant to reproduce the early time of network development in planar neural cell cultures. In simulations where the number of nodes is varied, we observe an optimal value of cell density for which information in the grid is maximized. In simulations in which the posttransmission latency time is varied, we observe that information increases as the latency time decreases and, for specific configurations of the grid, it is largely enhanced in a resonance effect

DEVICE FOR OBTAINING THREE-DIMENSIONAL CELL CULTURES, METHOD FOR THE IMPLEMENTATION THEREOF, AND USE OF SUCH DEVICE

A device for obtaining threedimensional cell cultures comprising: a sub strate (1); a plurality of micro-structures (2) which protrude from the surface of the sub strate (1) and are arranged on such substrate (1) according to a periodical grid so as to make the substrate (1) super hydrophobic. The device is characterised in that the micro-struc tures (2) have side walls at least partially nano-patterned and have projections (14) and recesses (16) alternated with a predetermined distance

Nonlinear graphene metamaterial

We demonstrate that the broadband nonlinear optical response of graphene can be resonantly enhanced by more than an order of magnitude through hybridization with a plasmonic metamaterial,while retaining an ultrafast nonlinear response time of ~1 ps. Transmission modulation close to ~1% is seen at a pump uence of ~0.03 mJ/cm^2 at the wavelength of ~1600 nm. This approach allows to engineer and enhance graphene's nonlinearity within a broad wavelength range enabling applications in optical switching, mode-locking and pulse shaping.Comment: The following article has been submitted to Applied Physics Letters. After it is published, it will be found at http://apl.aip.org

Evolution of modes in a metal-coated nano-fiber.

We report on the evolution of modes in cylindrical metal/dielectric systems. The transition between surface plasmon polaritons and localized modes is documented in terms of the real and imaginary parts of the effective refractive index as a function of geometric and optical parameters. We show the evolution process of SPP and localized modes. New phenomena of coupling between SPP and core-like modes, and of mode gap and super-long surface plasmon polaritons are found and discussed. We conclude that both superluminal light and slow light can be solutions of metallically coated dielectric fibers

Chronostratigraphic study of the Grottaperfetta alluvial valley in the city of Rome (Italy): investigating possible interaction between sedimentary and tectonic processes

We carried out geomorphologic and geological investigations in a south-eastern tributary valley of the Tiber River in Rome, the Grottaperfetta valley, aimed to reconstruct its buried geometry. Since results of the geomorphologic study evidenced anomalies of the stream beds, we performed geoelectric and boreholes prospecting to check whether recent faulting, rather than an inherited structural control, possibly contributed to the evolution of the alluvial valley. Vertical offsets of the stratigraphic horizons across adjacent boreholes were evidenced within the Late Pleistocene-Holocene alluvium and its substratum. In order to rule out the effects of irregular geometry of the alluvial deposits, we focussed on sectors where vertical offsets affected all the stratigraphic horizons (alluvium and pre-Holocene substratum), showing an increasing displacement with depth. We identified a site where repeated displacements occur coupled with a lateral variation of soil resistivity, and we drilled an oblique borehole aimed to cross and sample the possible fault zone affecting the terrain. A 7 cm thick granular layer, inclined 50°÷70° on the horizontal, was recovered 5 m b.g., and it was interpreted as the filling material of a fracture. The convergence of the reported features with independent evidence from geoelectric and geomorphologic investigations leads to hypothesize the presence of a faulting zone within the Holocene alluvial terrains and to propose the excavation of a trench to verify this hypothesis

Highly efficient human serum filtration with water-soluble nanoporous nanoparticles

Antonella Pujia1, Francesco De Angelis1,2, Domenica Scumaci3, Marco Gaspari3, Carlo Liberale1,2, Patrizio Candeloro1, Giovanni Cuda3, Enzo Di Fabrizio1,21BIONEM Laboratory, Department of Experimental and Clinical Medicine, University of Catanzaro “Magna Graecia”, Germaneto (CZ), Italy; 2IIT, Italian Institute of Technology, Genova, Italy; 3Proteomics and Mass Spectrometry Laboratory, Department of Experimental and Clinical Medicine, University of Catanzaro “Magna Graecia”, Germaneto (CZ), ItalyBackground: Human serum has the potential to become the most informative source of novel biomarkers, but its study is very difficult due to the incredible complexity of its molecular composition. We describe a novel tool based on biodegradable nanoporous nanoparticles (NPNPs) that allows the harvesting of low-molecular-weight fractions of crude human serum or other biofluids. NPNPs with a diameter of 200 nm and pore size of a few nm were obtained by ultrasonication of nanoporous silicon. When incubated with a solution, the NPNPs harvest only the molecules small enough to be absorbed into the nanopores. Then they can be recovered by centrifugation and dissolved in water, making the harvested molecules available for further analyses.Results: Fluorescence microscopy, gel electrophoresis, and mass spectrometry were used to show the enrichment of low-molecular-weight fraction of serum under physiological conditions, with a cut-off of 13 kDa and an enrichment factor >50.Conclusion: From these findings, we conclude that ability to tune pore size, combined with the availability of hundreds of biomolecule cross-linkers, opens up new perspectives on complex biofluid analysis, discovery of biomarkers, and in situ drug delivery.Keywords: nanoporous silicon, nanoparticle, biomarker discovery, human serum proteomics, harvestin